Magma Worm

Tremorsense (Imprecise) 100 feet — Tremorsense allows a monster to feel the vibrations through a solid surface caused by movement. It is an imprecise sense with a limited range (listed in the ability). Tremorsense functions only if the monster is on the same surface as the subject, and only if the subject is moving along (or burrowing through) the surface.

Fire Healing — As long as a magma worm is in contact with a fire or body of magma at least as large as itself, it gains fast healing 20. When struck by a magical fire effect from anything other than itself, a magma worm regains Hit Points equal to half the fire damage the effect would otherwise deal.

Inexorable — The magma worm recovers from the Paralyzed, Slowed, and Stunned conditions at the end of its turn. It's also immune to penalties to its Speeds and the Immobilized condition, and it ignores difficult terrain and greater difficult terrain.

Slough Skin — Frequency once per day

Trigger The magma worm would be affected by a condition or adverse effect (such as Cursed Metamorphosis)

Effect The magma worm negates the triggering condition or effect by sloughing an outer layer of its skin. Effects from artifacts, deities, or a similarly powerful source can't be avoided in this way.

Fast Swallow —

Fire Breath (fire, primal) — The magma worm breathes a blast of flame in a 60-foot cone that deals 18d6 fire damage to all creatures in the area (DC 41 Reflex save).

It can't use Fire Breath again for 1d4 rounds.

Magma Worm Venom (poison) — Saving Throw DC 41 Fortitude

Maximum Duration 6 rounds

Stage 1 1d6 poison damage and Drained 1 (1 round)

Stage 2 2d6 poison damage and drained 1 (1 round)

Stage 3 2d6 poison damage and Drained 2 (1 round).

Rock Tunneler — A magma worm can burrow through solid stone at a Speed of 20 feet. It can leave a tunnel if it desires, and it usually does.

Swallow Whole (attack) — Huge, 3d10+10 bludgeoning plus 2d6 fire, Rupture 36

The monster attempts to swallow a creature of the listed size or smaller that it has grabbed or restrained in its jaws or mouth. If a swallowed creature is of the maximum size listed, the monster can't use Swallow Whole again. If the creature is smaller than the maximum, the monster can usually swallow more creatures; the GM determines the maximum. The monster attempts an Athletics check opposed by the grabbed creature's Reflex DC. If it succeeds, it swallows the creature. The monster's mouth or jaws no longer grab a creature it has swallowed, so the monster is free to use them to Strike or Grab once again. The monster can't attack creatures it has swallowed.

A swallowed creature is Grabbed, is Slowed 1, and has to hold its breath or start suffocating. The swallowed creature takes the listed amount of damage when first swallowed and at the end of each of its turns while it's swallowed. If the victim Escapes this ability's grabbed condition, it exits through the monster's mouth. This frees any other creature grabbed in the monster's mouth or jaws. A swallowed creature can attack the monster that has swallowed it, but only with unarmed attacks or with weapons of light Bulk or less. The swallowing creature is Off-Guard against the attack. If the monster takes piercing or slashing damage equaling or exceeding the listed Rupture value from a single attack or spell, the swallowed creature cuts itself free. A creature that gets free by either Escaping or cutting itself free can immediately breathe and exits the swallowing monster's space.

Effect: Engulf and Swallow Whole

If the monster dies, a swallowed creature can be freed by creatures adjacent to the corpse if they spend a combined total of 3 actions cutting the monster open with a weapon or unarmed attack that deals piercing or slashing damage.

Thrash — The worm makes a Strike once against each creature in its reach. It can Strike up to once with its jaws, up to once with its stinger, and any number of times with its body. Each attack counts toward the worm's multiple attack penalty, but the multiple attack penalty doesn't increase until after it makes all the attacks.

Improved Grab —